The Improved Mechanical and Thermal Properties of Hemp Fibers Reinforced Polypropylene Composites with Dodecyl Bromide Modification

Hemp fibers-reinforced polypropylene (HP/PP) composite is strengthened and toughened by chemical treatment in a melt-blending process. The surface characters of the hemp fibers (HFs) treated by alkaline, γ-valerolactone (GVL) and dodecyl bromide (C12) are studied by FTIR. To evaluate the effect of each chemical treatment on HP/PP composites, the thermal stability, crystalline property, microstructure, mechanical property and rheology property have been studied. It is found that the composites with chemical treatment have improved mechanical property and thermal stability. Among those composites, the tensile modulus and maximum decomposition temperature (Tmax) of the dodecyl bromide treated composites are highest, and increase 18 % and 10 °C when compared with raw HFs. It is reveals that dodecyl bromide treatment could improve the mechanical and thermal properties of the composites. A possible reinforcing mechanical that hemp fibers react with dodecyl bromide in the composites have been proposed.